Not diving to greater than 30m/100ft unless with helium

[Adobo]

I agree, she had to be the nicest person on this board. The only person she was ever openly critical of - was herself.

She seemed to make a point of talking about her two biggest challenges: a very pronounced susceptibility to vertigo when presented with no visual reference and a seemingly unusually low tolerance for narcosis, which if I understood her various posts, made her very reluctant to dive more than just 100 feet without the benefit of helium in the mix.

It sounds like more people are FINALLY giving these two issues the consideration they deserve with respect to potential relevance to her fatality.

Many members seem to envision her as a very strong and capable diver. From my perspective, these two issues represent serious weaknesses (or at least vulnerabilities) when functioning in a high current, drift dive situation with no visual references and when drifting in water that she knew would cause her significant narcosis.

I'd like to hear people's thoughts on this but *not* tying back to TSandM as she was not unique in her approach of when to use helium.

DD's claim is that reluctance to dive to depths of greater than 30m/100ft without helium indicates unusually low tolerance for narcosis and therefore represents a weakness in a diver.

I'd like to know people's thoughts on the use of helium to mitigate the effects of narcosis and whether or not this is a "weakness" in a diver. I'd also like to know what alternative would be suggested.

 

[rhwestfall]

this will be interesting.....

(FWIW - my summer was AN/DP/Helitrox, but did not complete the Helitrox dives as schedules just crashed and burned)

 

[tomfcrist]

I don't think it signifies weakness at all. I think it signifies a persons unwillingness to take on what they believe is an unacceptable level of narcosis. The GUE bubbas subscribe to a theory that anything below 100' on air has an unacceptable risk of impairment. If a person chooses to drink their Kool-Aid, they should subscribe to that theory. NAUI is in the same boat, but uses 130' as the limit for non-helium dives. TDI is good to go at 180'. None of this means anything to the diver that sets their own limits of acceptable narcosis risk. As I have grown older and wiser, I appreciate the anti narcosis effects of helium on deeper dives...I like to keep my END shallower than 120. The different experiences I have had at 170' on air vs trimix is evidence enough for me that I am more "in control" of myself when breathing trimix. Would I use Helitrox for a 130' dive? Maybe. It depends on the conditions. I am not worried about someone thinking less of me because I show up with MIX in my tanks, mostly because I could care less what they think of MY personal choices.

 

[TMHeimer]

Being PADI I have never thought of using helium. My deep diving to 120+ feet has been very rare, but on those occasions I haven't felt any noticable effects of narcosis (I know we are affected somewhat and do things slower but maybe not notice). Not that it's at all important compared to one's safety, but I imagine helium costs a lot. Never heard of it above 130'.

 

[decompression]

I prescribe to the DIR ethos of keeping narcotic depths to 100'. Over many years and thousands of dives I've experienced and witnessed a vast majority that experience the beginning of or significant narcosis around 100'. I used to dive deep air when I was young and foolish and honestly if you've ever experienced an issue at +130' the limiting factors of high gas consumption and cognitive ability are very serious and can easily be addressed with helium.


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[abscuba]

I don't think this is a weakness on the diver at all. Helium is a tool and putting a blanket statement out generalizing a specific tool. I have personally gone 180+ on air, but those dives are kept very basic, have a lot of planning, in groups where every one has a good deal of experience. Now if I am going to penetrate deep into a wreck or start adding tasks then the helium tool will need to come out. If I am going deeper than 180 then it also becomes a trimix dive. It is very much based on comfort level of the dive team. We have worked our way down to the depths we work at and we are always working to improve. It would be nice to always have trimix available and if we all had submarines then things would be even easier. Logistics and experience don't always allow that which is why a team should have its limits and work down to what the group is comfortable with.

 

[eelnoraa]

I don't think it has to do with weakness at all. Using a known safer method to get a job done is a no brainer IMO. If the only reason not going to He is because of cost, it is risk vs cost. I have to ask, if He is cost as much as air, would anyone not use He?

An analogy I can think of is safety option in cars, like ABS, airbags and traction control. Does choosing these options reflect a driver's skill?

 

[Akimbo]

People need to find their own limits and comfort level. I am personally comfortable using air in the 200-220' range but have a lot of history to back it up. Narcosis doesn't instantly cause you lose your mind after crossing a threshold, it sneaks up on you gradually and is manageable to a considerable degree. IMHO, diving Trimix because of scary stories is foolish on many levels. It is important to learn how you react to narcosis slowly and gradually before you select a threshold.

 

[Lorenzoid]

At the depths in question, maybe it's not so much "impairment" as just wanting to be able to think that much more clearly or to be able to rememb in minute detail what you saw down there. Maybe poking around a wreck at 130 feet you wouldn't feel anything unusual, but for someone with a specific task to attend to helium might just make the difference in clarity of thinking. Or if something goes wrong, and you want to be as sharp as possible to nip it in the bud before it cascades ....

 

[Akimbo]

At the depths in question, maybe it's not so much "impairment" as just wanting to be able to think that much more clearly or to be able to rememb in minute detail what you saw down there...

I have done some pretty complex work in the 160-180' range without much concentration or the need for excessive preparation. I'm confident that I am not somehow "exceptional" since many people I have dove with have done the same. For me. 200-250' requires progressively more preparation and concentration but have never felt that I could not handle the unforeseen. The actual depth you personally react to these constraints is not important, finding them is.

You need to know your limits when diving in a soft or hard overhead environments. You never know when air or lean nitrox is all there is left to save your butt so you better have some idea how to manage the consequences.